Biofuels in Transition: Integrating Prospective LCA and Energy System Optimization Modeling

This study explores the role of two lignocellulosic pathways, REDIFUEL and lignocellulose-to-naphtha, within the Belgian energy transition by integrating prospective life cycle assessment (LCA) with an energy system optimization model. The results show that system performance is primarily driven by resource imports rather than individual technology choices. Advanced biofuels may contribute cost-effectively to the energy transition by 2030, whereas biobased chemicals only become significant by 2050. However, their deployment increases reliance on wood and renewable hydrogen, leading to higher environmental impacts in several impact categories and a decline in the energy return on investment (EROI). More broadly, scenarios relying on imported renewable hydrogen are associated with increased upstream impacts, particularly for water depletion and land use, and lower EROI at the point of use. These results highlight a shift from local emission reductions to upstream, resource-related impacts occurring largely outside Belgium. Overall, the findings highlight that system-level assessments can yield different conclusions from product-level studies and are essential for capturing resource competition, cross-sector interactions, and burden-shifting effects.